Vehicle Support Frames with Interlocking Features for Joining Members of  Dissimiliar Materials

ABSTRACT

The present disclosure relates to various vehicle cross-member assemblies and methods of manufacturing the same. The various vehicle cross-member assemblies have rails composed of dissimilar materials.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation and claims the benefit of U.S. Patent Provisional Ser. No. 61/512,559 titled “Vehicle Support Frames with Interlocking Features for Joining Members of Dissimilar Materials” filed Jul. 28, 2011, which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to vehicle support frames with members having dissimilar materials and methods for manufacturing the same.

BACKGROUND

Conventional vehicle support frames can be composed of different materials including, for example, steel, aluminum and reinforced polymer composites. Vehicle manufacturers attempt to strike the balance between weight reduction and structural rigidity. It is desirable to design lightweight cross-members for full-sized light truck frames. Aluminum cross-members can be designed to achieve up to 50% weight reduction while still meeting performance targets. Aluminum cross-members have high potential for building lightweight truck frames. Joining aluminum members to steel frame rails also presents challenges especially when both parts are closed-section tubular components. Additionally, it can be costly to retool existing manufacturing facilities to handle complex techniques of joining dissimilar materials.

Some existing references within the art teach the use of mechanical fasteners to secure two rails made of dissimilar materials together. These techniques, however, are less desirable. These mechanical features include fasteners, which can increase costs and manufacturing complexity. One patent reference teaches the use of an overlapping configuration for the rails of dissimilar materials. A first and second structural member sandwiches one end of a third structural member and adhesive is applied there between. The second structural member is thereafter welded to the first structural member. U.S. Patent Publication No. 20090188206, titled “System and Method for Joining Dissimilar Materials” teaches an overlapping configuration which is more suitable for collinear-structural-member connection as opposed to intersecting- or angled-structural-member connection, i.e., side rail to cross-member connections. Accordingly, a method of manufacturing a vehicle cross-member assembly does not appear to be disclosed therein.

Another patent publication, U.S. Patent Publication No. 2006/0032895, titled “Method for Joining Axle Components” discusses joining two tubes composed of the same or dissimilar material using magnetic forming. This process uses a forming band placed at an opposite end of an electromagnetic actuator in order to form multiple tubes; therefore, more limited configurations are available for this assembly. For example, a sleeve or forming band between multiple tubes does not appear to be taught. This process is more expensive and requires more energy than most welding and/or mechanical locking techniques.

Therefore, it is desirable to have improved interconnecting techniques for joining two structural members composed of dissimilar materials.

SUMMARY

The present disclosure addresses one or more of the above-mentioned issues. Other features and/or advantages will become apparent from the description which follows.

One exemplary embodiment relates to a method of manufacturing a vehicle cross-member assembly, the method includes the steps of: journaling an interconnecting member composed of a first material onto a first rail composed of a second material; and welding the interconnecting member to a second rail composed of a different material than the first rail.

Another exemplary embodiment relates to a vehicle cross-member assembly, having: a first rail composed of a first material; a second rail composed of a second material; and an interconnecting member composed of the second material adhered to the first rail and journaled onto the first rail. The interconnecting member is welded to the second rail.

Another exemplary embodiment relates to another method of manufacturing a vehicle cross-member assembly, the method including: forming a hem-lock between a first rail having a first material composition and an interconnecting member having a second material composition; and welding the interconnecting member to a second rail having a different material composition than the first rail.

Another exemplary embodiment relates to another vehicle frame assembly, including: a first rail having a first material composition; a second rail having a second material composition; and an interconnecting member hem-locked to the first rail and welded to the second rail.

One advantage of the present disclosure is that it enables the use of welding techniques to join two or more frame assembly components composed of dissimilar materials. This disclosure teaches the use of an interconnecting member between frame components that can be attached to one rail using one joining technique and connected to another rail using a simple mechanical attachment technique, e.g., welding.

Another advantage of the present disclosure is that it teaches the manufacture and use of light-weight vehicle structural frames that can be utilized with vehicles of different sizes, including full-sized truck frames. The weight reduction for the disclosed frame assemblies compared to contemporary structural frames can be as great as 50%. Fuel efficiency and performance can be enhanced by the use of the disclosed frame assemblies.

Another advantage of the present disclosure is that it teaches joining techniques for structural members having dissimilar material composition and a closed-section configuration. Structural members can be positioned at any angle with respect to each other.

Another advantage of the present disclosure is that it teaches the use of aluminum structural members in a vehicle frame that can be used in relatively heavy duty applications, e.g., pick-up trucks.

Joining a longitudinal rail and lateral rail composed of dissimilar materials will be explained in greater detail below by way of example with reference to the figures, in which the same reference numbers are used in the figures for identical or essentially identical elements. The above features and advantages and other features and advantages of the present teachings are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings. In the figures:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of a vehicle support frame assembly.

FIG. 2 is a perspective view of a cross-member and interconnecting member according to one step of an exemplary method of manufacturing a vehicle support frame assembly.

FIG. 3 is a perspective view of the cross-member and interconnecting member of FIG. 2 according to another step in the method of manufacturing.

FIG. 4 is a perspective view of the cross-member and interconnecting member of FIG. 2 according to another step in the method of manufacturing.

FIG. 5 is a perspective view of the cross-member and interconnecting member of FIG. 2 according to another step in the method of manufacturing.

FIG. 6 is a perspective view of another exemplary interconnecting member and cross-member.

FIG. 7 is a cross-sectional view of the interconnecting member and cross-member of FIG. 6 through line 7-7.

FIG. 8 is a perspective view of another exemplary interconnecting member and cross-member.

FIG. 9 is a cross-sectional view of the interconnecting member and cross-member of FIG. 8 through line 9-9.

FIG. 10 is a cross-sectional view of the interconnecting member and cross-member of FIG. 8 taken along line 10-10.

FIG. 11 is a perspective view of another exemplary embodiment of an interconnecting member and cross-member.

FIG. 12 is a cross-sectional view of the interconnecting member and cross-member of FIG. 11 taken along line 12-12.

FIG. 13 is a perspective view of another exemplary embodiment of an interconnecting member and cross-member.

FIG. 14 is a cross-sectional view of the interconnecting member and cross-member of FIG. 13 taken along line 14-14.

FIG. 15 is a perspective view of another exemplary embodiment of an interconnecting member and cross-member.

DETAILED DESCRIPTION

Referring to the drawings, wherein like characters represent examples of the same or corresponding parts throughout the several views, there are shown vehicle support frames having joined structural members composed of different materials. Particularly, lighter weight aluminum cross-members are joined to steel side rails in most embodiments. The aluminum and steel members are joined through an interconnecting member juxtaposed therebetween. The disclosed interconnecting members mitigate several challenges incumbent with joining dissimilar materials by teaching one facet of attachment between the interconnecting member and cross-member and another form of attachment between a side rail and interconnecting member. In some embodiments, one end of the interconnecting member is joined to the cross-member using mechanical interlocking features (e.g., adhesives or crimping). The attachment techniques used to attach the side rail to the assembly at another end of the interconnecting member is different from the prior, e.g., MIG welding. By utilizing a combination of different attachment techniques and an interconnecting member, structural members of incompatible material composition for a single attachment technique can be robustly joined.

Any combination of differing attachment techniques can be used including, for example, the use of adhesives, brazing, welding, crimping, riveting, hydro-forming or soldering. The disclosed interconnecting members facilitate the use of lower weight materials in vehicle support frames. The teachings herein are applicable to any type of vehicle frame including frames for pickup trucks, vans, minivans, sports utility vehicles, sedans, coupes, commercial vehicles, and all utility vehicles.

Referring now to FIG. 1, there is shown therein a vehicle support frame 10. The illustrated support frame 10 is configured for use in a pickup truck. Support frame 10 (as shown) is taken from the rear section of the truck frame, which supports the truck bed (not shown). Side rails (or structural members) 20 and 30 extend longitudinally with respect to the assembly and the vehicle. In the shown embodiment, side rails 20, 30 can be composed of steel and formed via any standard forming process, e.g., stampings, hydro-forms, or roll forming. The rearward ends of the side rails are interconnected through a forward steel cross-member 70 and a rearward steel cross-member 40. Attached to cross-member 40 is a tow hitch 50. Each end of the rails 20 and 30 are fitted with a side bracket 60 for interconnecting cross-member 40 with the rails and for connecting the rails to other vehicle structure (e.g., the truck bed, rear fascia or bumper, etc.).

At the frontward end of the support frame 10, shown in FIG. 1, there is another steel cross-member 70 intersecting each side rail 20, 30. As shown, side rail 30 is welded to cross-member 70. The vehicle support frame 10 also includes a subassembly 80 for mounting spare tires. Subassembly 80 includes two laterally extending aluminum cross-members 90. Cross-members 90 support a subframe 100 for a spare tire. A winch (not shown) secures the tire to the subframe through orifice 110. The illustrated subframe 100 is stamped. The subframe 100 can also be formed, for example, via die casting or other forming techniques. Subframe 100 is composed of aluminum but can also be composed of different materials, e.g., aluminum, an aluminum alloy, steel, or a polymer.

Aluminum cross-members 90 are configured to secure the subframe 100 onto the side rails 20 and 30. Cross-members 90 extend laterally with respect to the frame assembly and vehicle. Cross-members 90 are fitted with an interconnecting member 120, as discussed hereinbelow. Interconnecting members 120 are attached to the cross-members through the use of one attachment technique and also attached to the side rail using a different attachment technique. In the illustrated embodiment, interconnecting members 120 are adhered to cross-members. Interconnecting members are further attached to the side rails 20 and 30 via MIG welding.

The cross-member 90 and interconnecting member 120 of FIG. 1 are further discussed with respect to FIGS. 2 through 5. One method of joining the aluminum cross-member and steel interconnecting member is shown. The method includes: (1) forming the interconnecting member, which in this case is a steel plate having a length approximately equal to the perimeter of the aluminum tube (as shown in FIG. 2); (2) applying adhesive to one side of the plate and the tube (as also shown in FIG. 2); (3) wrapping the plate around the aluminum tube (as shown in FIG. 3); and (4) forming the tube and plate against a mandrel to form a mechanical interlock therebetween (e.g., at least one crimp as shown in FIG. 5).

Referring now to FIG. 2, there is shown therein cross-member 90 and an interconnecting member in the form of a steel plate 120 pre-assembly. Cross-member 90 is a hollow rectangular tube. Interconnecting member 120 is a flat steel plate. The dimensions of the cross-member 90 and interconnecting member can vary according to structural demands and performance characteristics. In this embodiment, the cross-member has rounded corners 130. As shown in FIG. 2, edge 140 of the cross-member and edge 150 of the interconnecting member are aligned. On an outer surface 160 of the cross-member 90 an adhesive 170 is applied. Any type of adhesive can be used, e.g., a one- or two-part epoxy. The steel plate 120 also has the adhesive 170 applied to surface 180.

As shown in FIG. 3, interconnecting member 120 is formed over the end of cross-member 90. Interconnecting member 120 can be formed, for example, using a stamping process or mandrel. As shown in FIG. 4, interconnecting member 120 is formed against cross-member 90 so as to be flush with surface 160 of cross-member. Interconnecting member 120 is folded around the entire perimeter of cross-member 90. A mandrel 190 is inserted in the cross-member 90. Mandrel 190 has formed therein two recesses 200 (as shown in FIG. 5). Interconnecting member 120 and cross-member 90 are formed against mandrel 190, as shown in FIG. 4. An external die (not shown) is applied to the interconnecting member 120 and cross-member 90 to form a crimp 210 (or impression) therein. A mechanical interlock, in this case the crimp 210, is thereby formed in interconnecting member 120 and cross-member 90. Mandrel 190 is then removed, as shown in FIG. 5. Two crimps 210 are formed in the interconnecting member 120 and cross-member 90 in this embodiment. Interconnecting member 120 is thereafter welded to a steel side rail (e.g., 20 or 30 as shown in FIG. 1).

Referring now to FIGS. 6-7, there is shown therein another exemplary embodiment of a portion of a vehicle cross-frame assembly 300. The assembly 300 includes a side rail 310, interconnecting member 320 and a cross-member 330. In this embodiment, the interconnecting member 320 is a sleeve that encircles one end of the cross-member 330. Side rail 310 is fitted or intersected with sleeve 320 and cross-member 330. The interconnecting member 320 and side rail 310 are composed of steel. Cross-member 330 is composed of aluminum.

An end of cross-member 330 is crimped with the interconnecting member 320, as shown in FIGS. 6 and 7. A first crimp 340 and a second crimp 350 are commonly formed in the cross-member 330 and interconnecting member 320. The vehicle defines a longitudinal axis, L1, as designated in FIG. 6. In this embodiment, crimps 340, 350 define a longitudinal centerline, e.g., L2 and L3, on the outer surface of the interconnecting member 320. Crimps are formed so that the longitudinal center lines of the crimps, L2 and L3, extend parallel to the longitudinal axis of the vehicle, L1. Crimps 340 and 350 are also formed so that when the cross-member 330 and interconnecting member 320 are inserted in the side rail 310, crimps 340, 350 are enclosed by side rail 310. In the shown embodiment, crimps 340, 350 are position proximate a center-section of the side rail 310, as shown in FIG. 7.

In other embodiments, crimps can be positioned outside of the intersection between the cross-member 330 and side rail 310. Crimps 340, 350, as shown in FIG. 6, extend 360 degrees across the outer surface of the interconnecting member 320 and cross-member 330. Crimps 340, 350 form a mechanical interlock between interconnecting member 320 and cross-member 330. In another embodiment, interconnecting member 320 is secured onto the cross-member 330 by the use of an adhesive applied to an overlapping section of interconnecting member and cross-member, e.g., as discussed with respect to the embodiment shown in FIGS. 2-5. Adhesive can be activated via a brazing process, otherwise thermally, by humidity, electrically or by other attachment processes. At location 360 on the interconnecting member 320, for example, the interconnecting member is attached to the side rail 310 via welding. Side rail 310 and interconnecting members 320 are composed of steels that have compatible weld qualities or characteristics.

Turning now to the illustrated embodiment of FIGS. 8-10, there is shown therein another exemplary embodiment of a portion of a vehicle support frame assembly 400. The assembly 400 includes a side rail 410, interconnecting member 420 and a cross-member 430. Interconnecting member 420 is a sleeve that encircles one end of the cross-member 430. Side rail 410 is intersected with interconnecting member 420 and cross-member 430. The interconnecting member 420 and side rail 410 are composed of steel for compatibility of attachment through weld. Cross-member 430 is composed of a lighter weight material, e.g., aluminum.

In the illustrated embodiment of FIGS. 8-10, the cross-sectional area of the interconnecting member 420 and cross-member 430 is reduced where the interconnecting member is crimped at 440 as shown in FIG. 9. A plurality of crimps 450 are commonly formed in the cross-member 430 and interconnecting member 420, as shown in FIG. 10. A vehicle defines a lateral axis, L4, as designated in FIG. 8. In this embodiment, crimps 450 define a longitudinal centerline, e.g., L5, on the outer surface of the interconnecting member 420. Crimps are formed so that the longitudinal center lines of the crimps, L5, extends parallel to the lateral axis of the vehicle, L4.

In other embodiments, crimps 450 can be positioned outside of the intersection between the cross-member 430 and side rail 420. In another embodiment, interconnecting member 420 is secured onto the cross-member 430 by the use of an adhesive applied to an overlapping section of interconnecting member 420 and cross-member 430.

Referring now to FIGS. 11-12, there is shown therein another exemplary embodiment of a portion of a vehicle frame assembly 500. In this embodiment, an interconnecting member 510 and side rail 520 of common material selection are shown. Cross-member 530 is composed of aluminum. Side rail 520 is intersected with interconnecting member 510 and cross-member 530, as shown. Interconnecting member 510 extends over an end of the cross-member 530. Interconnecting member 510 includes four flanges 540. Flanges 540 are formed by removing material at the corners 550 of interconnecting member 510 thereby forming a notch in corner 550. Flanges 540 are folded over the edge of cross-member 530 (or into the cross-member) thereby creating a hem-lock at the folded edge 555 of each flange 540 between the interconnecting member 510 and cross-member 530. The flange 540 and cross-member 530 are attached at hem-lock 555. At another location on the interconnecting member, e.g., 560, interconnecting member 510 can be welded (or otherwise attached) to side rail 520, as shown in FIGS. 11-12. In this embodiment, interconnecting member 510 is further secured onto the cross-member 530 by the use of an adhesive 570 applied between the overlapping sections of interconnecting member 510 and cross-member 530.

In FIGS. 13-14, there is shown a portion of another alternative embodiment of a vehicle frame assembly 600. The frame assembly 600 has a hem-lock 605 between a cross-member 610 and interconnecting member 620. Interconnecting member 620 and a side rail 630 are of a material selection that facilitates joining through welding (e.g., steel to steel, high-carbon steel to low-carbon steel, and steel to tungsten). Cross-member 610 is composed of a light weight material, such as aluminum or titanium. Side rail 620 is fitted or intersected with interconnecting member 620 and cross-member 610, as shown in FIGS. 13-14. Cross-member 610 extends through an end of the interconnecting member 620. Cross-member 610 includes four flanges 640. Flanges 640 are formed by removing material at corners 650 of cross-member 610 thereby forming a notch in corner 650. Flanges 640 are formed over the edge of interconnecting member 620 (or onto the interconnecting member) thereby creating a hem-lock 605 at said edge between the interconnecting member 620 and cross-member 610. The hem-locks 605 between flange 640 and interconnecting member 620 are the locations at which the interconnecting member and cross-member are attached. At another location on the interconnecting member, e.g., 660, interconnecting member 620 can be welded (or otherwise attached) to side rail 630, as shown in FIG. 14. Interconnecting member 620 is further secured onto the cross-member 610 by the use of an adhesive 670 applied between the overlapping sections of interconnecting member 620 and cross-member 610.

Now with reference to FIG. 15, there is shown therein a perspective view of a portion of another vehicle support frame assembly 700. More than one interconnecting member can be utilized at one end of the cross-member in the frame assemblies. Shown in FIG. 15 is a cross-member 710 with multiple interconnecting members 720 attached thereto. Interconnecting members 720 are composed of steel. Cross-member 710 is composed of aluminum. On surface 730 of the cross-member 710, interconnecting member 720 is affixed to the cross-member. On surface 740 of the cross-member 710, interconnecting member 720 is affixed to cross-member 710. In this embodiment, interconnecting members 720 are oblong in configuration. Interconnecting members 720 included a beveled edge, e.g., 750. In other embodiments, interconnecting members 720 have different configurations, e.g., rectangular shapes, straight edges, and jagged surfaces. In another embodiment, a mechanical interlock is formed between the interconnecting members 720 and cross-member 710, e.g., crimps, impressions, concavities, protrusions, hem-locks or other attachment schemes. Interconnecting members 720 are welded to a side rail after insertion therein.

There is also taught herein methods of manufacturing a vehicle cross-member assembly. One method includes the steps of: (i) journaling an interconnecting member composed of a first material onto a first rail composed of a second material (e.g., as shown in FIGS. 2-4); and (ii) welding the interconnecting member to a second rail composed of a different material than the first rail (e.g., as taught with respect to FIGS. 2-5). The interconnecting member can be journaled onto the first rail using available forming techniques including, e.g., stamping, cold-forming, press-fitting or hydro-forming. The method also includes adhering the interconnecting member to the first rail. Adhering the interconnecting member to the first rail can include applying an adhesive or bonding agent, for example, to the interconnecting member and/or first rail. Adhesives can also be applied between any of the interconnecting members and cross-member or the interconnecting member and the side rails. Any type of adhesive can be used, e.g., a one- or two-part epoxy is compatible with the illustrated designs. The ends of the interconnecting member and cross-member can also have a brazing material included therebetween to enhance their connection and serve as corrosion mitigation. The ends of the mixed material overlapping joint can have a polymer or other sealing material.

In one embodiment of the aforementioned method, the method includes press-fitting the interconnecting member and the first rail together (e.g., as shown in FIGS. 4-5). During the press-fitting process an additional crimp can be formed in the interconnecting member and/or first rail or cross-member, as also shown in FIGS. 4-5.

Crimps can be formed in different positions with respect to the first rail (or cross-member). For example, as shown in FIGS. 6-7, one method of manufacturing a vehicle cross-member assembly includes forming the crimps so that a longitudinal center line of the crimps extends parallel to a longitudinal axis of the vehicle. In another exemplary embodiment of the method of manufacturing a vehicle cross-member assembly the method includes forming the crimps so that a longitudinal center line of the crimps extends parallel to a lateral axis of the vehicle, e.g., as shown in FIGS. 8-10. Crimps can be formed using available forming techniques, e.g., stamping, cold-forming, press-fitting or hydro-forming.

The manufacture of other types of vehicle cross-member assemblies is also disclosed herein. One method of manufacturing a vehicle cross-member assembly includes the following steps: (i) forming a hem-lock between a first rail having a first material composition and an interconnecting member having a second material composition (e.g., shown in FIGS. 11-14); and (ii) welding the interconnecting member to a second rail having a different material composition than the first rail. In one embodiment of this method, the method includes forming a plurality of flanges in the interconnecting member (as shown in FIG. 11) or the first rail (as shown in FIG. 13) and folding the flanges over an edge of the other of the interconnecting member or first rail. At the corner of the flanges material is removed, e.g., as shown in FIGS. 11 and 13. Material can be removed, for example, by stamping, lathing, milling or other removal techniques. In the embodiments, shown in FIGS. 11-14 an adhesive is applied between the interconnecting member and cross-member (or rail). Any type of adhesive or bonding material can be used. The adhesive can be applied before or after assembly.

It will be appreciated that the members illustrated (e.g., the interconnecting members, side rails and cross-members) can be composed of various materials including, for example, steel, aluminum, magnesium, titanium, tungsten and reinforced polymer composites. Attachment techniques for the sleeve to the side rail is not limited to MIG welding but can include laser welding, spot welding, brazing, the use of a fastener, soldering, clinging or crimping. Sleeves and rails can be formed using manufacturing techniques including, molding, casting, lathing, hydro-forming, stamping or an extrusion processes.

The material composition of each member can be changed from those disclosed with respect to the illustrated embodiments. For example, in some embodiments the cross-member is composed of titanium or a reinforced polymer. Any one of the side rails or interconnecting members can commonly be composed of the same material or different material. As taught, the weld-compatibility of the interconnecting member and the side rail are taken into consideration. In other embodiments the interconnecting member is coupled to the side rail using a different attachment technique (e.g., mechanical interlocking and/or the use of adhesives) and the interconnecting member is welded to the cross-member. In another embodiment, the interconnecting member is formed with the side rail and a subsequent weld between the side rail and interconnecting member is unneeded. It should also be appreciated that the terms “material” and “material composition” are inexact approximations. Any items referred to as having a same material composition includes any items with substantially the same material composition, material properties, or performance characteristics.

It will also be appreciated that interconnecting members can be of any size, shape or configuration and are not limited to sleeves or bars. For example, in other embodiments, interconnecting members are rectangular in shape and clamped on to a receptor in the cross-member to provide a surface for subsequent welding.

While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims. 

1. A method of manufacturing a vehicle cross-member assembly, comprising: journaling an interconnecting member composed of a first material onto a first rail composed of a second material; and welding the interconnecting member to a second rail composed of a different material than the first rail.
 2. The method of claim 1, further comprising adhering the interconnecting member to the first rail.
 3. The method of claim 1, further comprising: press-fitting the interconnecting member and the first rail together.
 4. The method of claim 3, wherein the press-fitting includes: forming at least one set of crimps in the interconnecting member and first rail.
 5. The method of claim 4, wherein the forming at least one set of crimps includes forming the crimps so that a longitudinal center line of the crimps extends parallel to a lateral axis of a vehicle.
 6. The method of claim 4, wherein the forming at least one set of crimps includes forming the crimps so that a longitudinal center line of the crimps extends parallel to a longitudinal axis of a vehicle.
 7. A vehicle cross-member assembly, comprising: a first rail composed of a first material; a second rail composed of a second material; and an interconnecting member composed of the second material adhered to the first rail and journaled onto the first rail; wherein the interconnecting member is welded to the second rail.
 8. The assembly of claim 7, further comprising: at least one set of crimps commonly formed in the interconnecting member and first rail.
 9. The assembly of claim 8, wherein a longitudinal center line of the crimps extends along a lateral axis of a vehicle.
 10. The assembly of claim 9, wherein a longitudinal center line of the crimps extends along a longitudinal axis of a vehicle.
 11. A method of manufacturing a vehicle cross-member assembly, comprising: forming a hem-lock between a first rail having a first material composition and an interconnecting member having a second material composition; and welding the interconnecting member to a second rail having a different material composition than the first rail.
 12. The method of claim 11, wherein the forming a hem-lock includes: forming a plurality of flanges in one of the interconnecting member or first rail; and folding the flanges over an edge of the other of the interconnecting member or first rail.
 13. The method of claim 12, wherein the forming a plurality of flanges includes removing material from a corner of the interconnecting member or first rail.
 14. The method of claim 12, further comprising: applying adhesive between the interconnecting member and first rail.
 15. A vehicle frame assembly, comprising: a first rail having a first material composition; a second rail having a second material composition; and an interconnecting member hem-locked to the first rail and welded to the second rail.
 16. The vehicle frame assembly of claim 15, wherein the first rail is configured to extend longitudinally with respect to the assembly; and wherein the second rail is configured to extend laterally with respect to the assembly.
 17. The vehicle frame assembly of claim 16, wherein the interconnecting member or first rail comprises a plurality of flanges.
 18. The vehicle frame assembly of claim 17, further comprising a notch formed between at last two of the plurality of flanges.
 19. The vehicle frame assembly of claim 17, wherein the plurality of flanges are formed in the interconnecting member and fold into the first rail.
 20. The vehicle frame assembly of claim 17, wherein the plurality of flanges are formed in the first rail are fold onto the interconnecting member. 